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US6253537B1 - Revolution speed control method in gas turbine shutdown process - Google Patents

Revolution speed control method in gas turbine shutdown process Download PDF

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Publication number
US6253537B1
US6253537B1 US09/380,460 US38046099A US6253537B1 US 6253537 B1 US6253537 B1 US 6253537B1 US 38046099 A US38046099 A US 38046099A US 6253537 B1 US6253537 B1 US 6253537B1
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US
United States
Prior art keywords
rotational speed
time
gas turbine
load
decreased
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US09/380,460
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English (en)
Inventor
Kiyoshi Suenaga
Yukihiro Hashimoto
Yasuoki Tomita
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Mitsubishi Power Ltd
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Mitsubishi Heavy Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Heavy Industries Ltd filed Critical Mitsubishi Heavy Industries Ltd
Assigned to MITSUBISHI HEAVY INDUSTRIES, LTD. reassignment MITSUBISHI HEAVY INDUSTRIES, LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: HASHIMOTO, YUKIHIRO, SUENAGA, KIYOSHI, TOMITA, YASUOKI
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Publication of US6253537B1 publication Critical patent/US6253537B1/en
Assigned to MITSUBISHI HITACHI POWER SYSTEMS, LTD. reassignment MITSUBISHI HITACHI POWER SYSTEMS, LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: MITSUBISHI HEAVY INDUSTRIES, LTD.
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Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
    • F02C9/00—Controlling gas-turbine plants; Controlling fuel supply in air- breathing jet-propulsion plants
    • F02C9/26—Control of fuel supply
    • F02C9/46—Emergency fuel control
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D21/00—Shutting-down of machines or engines, e.g. in emergency; Regulating, controlling, or safety means not otherwise provided for
    • F01D21/04—Shutting-down of machines or engines, e.g. in emergency; Regulating, controlling, or safety means not otherwise provided for responsive to undesired position of rotor relative to stator or to breaking-off of a part of the rotor, e.g. indicating such position
    • F01D21/06—Shutting-down
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2270/00—Control
    • F05D2270/01—Purpose of the control system
    • F05D2270/02—Purpose of the control system to control rotational speed (n)
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2270/00—Control
    • F05D2270/01—Purpose of the control system
    • F05D2270/09—Purpose of the control system to cope with emergencies
    • F05D2270/091—Purpose of the control system to cope with emergencies in particular sudden load loss
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2270/00—Control
    • F05D2270/01—Purpose of the control system
    • F05D2270/11—Purpose of the control system to prolong engine life
    • F05D2270/112—Purpose of the control system to prolong engine life by limiting temperatures

Definitions

  • the present invention relates generally to a rotational speed control method in a process for stopping a gas turbine, and specifically to an operational method for controlling a rotational speed in the stopping process so as to avoid excessive stress to be caused in a moving blade.
  • FIG. 3 is a perspective view of a gas turbine moving blade, wherein numeral 11 designates a moving blade, numeral 12 designates a platform thereof and the moving blade 11 is rotated by a high temperature combustion gas G in a direction R.
  • a gas turbine moving blade operated at a rated rotational speed, when a load decreases to no load and fuel is shut off for a stop of the operation, then excessive thermal stress and centrifugal force arise in the stopping process, as described later, and a crack may occur in the blade.
  • FIGS. 2 are explanatory views of the transition of the occurrence of stress in the blade in the above mentioned gas turbine stopping process.
  • FIG. 2 ( a ) shows a load state
  • FIG. 2 ( b ) shows a rotational speed state
  • FIG. 2 ( c ) shows a metal temperature state
  • FIG. 2 ( d ) shows the state of stress at the point A of the moving blade 11 of FIG. 3 .
  • a gas turbine is operated with 4/4 load (full load) until time t 1 , on the time axis.
  • Fuel is throttled starting from the time t 1 to time t 2 , when the load decreases to 0/4 load (no load).
  • a gas turbine rotor is kept rotated in a state of no load until time t 3 when the fuel is shut off, and then the load comes to a zero state rapidly.
  • FIG. 2 ( b ) corresponding to the load transition of FIG. 2 ( a ), the gas turbine is usually kept operated at a rated rotational speed from the time t 2 , when the load becomes 0/4, to the time t 3 , when the fuel is shut off.
  • the rotational speed then decreases rapidly to come to a stop.
  • the metal temperature is shown with respect to point A of the moving blade 11 and point B of the platform 12 , both shown in FIG. 3 .
  • the metal temperature is kept at a high temperature level.
  • the fuel is then throttled starting from the time t 1 , and the metal temperature goes down until the time t 2 of the 0/4 load to then be kept constant until the time t 3 while the state of the 0/4 load continues.
  • the thermal capacity is larger in the platform 12 than in the moving blade 11 , the metal temperature is kept higher at the point B than at the point A until the time t 3 .
  • FIG. 2 ( d ) shows a state of stress at the point A of the moving blade 11 .
  • the stress is constant until the time t 1 and then decreases slightly as the load decreases to the time t 2 when the load becomes the 0/4 load. Thereafter, even in the state of no load from the time t 2 to the time t 3 , the stress decreases slightly further.
  • the time t 4 when the largest differential temperature ⁇ T occurs as shown in FIG. 2 ( c ), an excessive thermal stress is generated.
  • a centrifugal force in proportion to the rotational speed squared acts. Hence a large force is added to the point A, and a crack may occur, as the case may be, to break the blade.
  • a rotational speed control method in a gas turbine stopping process wherein, in a process that a gas turbine operated at a rated rotational speed is decreased in load to be operated with no load and is then shut off from fuel for stopping operation, a gas turbine rotational speed is controlled to be decreased so that a centrifugal force caused thereby is decreased as well as fuel being throttled so that the differential temperature in a moving blade is made smaller. Thereby the total stress caused by the centrifugal force and the differential temperature is thereby decreased, and breakage of the moving blade can be prevented.
  • the present invention provides the following.
  • a rotational speed control method in a gas turbine stopping process comprises a gas turbine operated at a rated rotational speed with a full load being decreased in load gradually so as to be operated with no load. It is then shut off from fuel for stopping of the operation.
  • the rotational speed of the gas turbine is controlled to be decreased at a predetermined rate starting from the time when a power supply from the gas turbine becomes zero while the gas turbine is decreased in load gradually so as to be operated with no load.
  • the rotational speed is further controlled to be decreased to about 60% of the rated rotational speed at the time when the fuel is shut off; then the rotational speed is decreased freely.
  • the load is decreased gradually to a no load operation
  • the gas turbine rotational speed is decreased at a predetermined rate from the rated rotational speed starting from the time when power generation is stopped, for example, when a power supply from the gas turbine becomes zero, or when a generator ceases power generation, and further control is done to decrease the rotational speed to about 60% of the rated rotational speed at the time when the fuel is shut off completely.
  • the level of about 60% of the rated rotational speed is decided in consideration of restrictions of a critical rotational speed in terms of shaft or blade vibration and compressor surge.
  • the rotational speed is decreased to about 60% of the rated rotational speed at the time when the fuel is so shut off, and thereafter the rotational speed is also lower than that of the prior art case.
  • the centrifugal force which is proportional to the rotational speed squared, can be decreased greatly as compared with the prior art. Also, as the rotational speed decreases, less fuel is needed and the metal temperature at the time of fuel shut-off can also be decreased as compared with the prior art. As a result of the decreased centrifugal force and the decreased metal temperature, the total stress of caused by the centrifugal force and caused by the differential temperature occurring in the moving blade after the fuel shut-off can be mitigated greatly, there occurs no case of breakage of the moving blade, and the life thereof can be greatly elongated.
  • FIGS. 1 are explanatory views of the function of a rotational speed control method in a gas turbine stopping process of an embodiment according to the present invention, wherein FIG. 1 ( a ) shows a state of load in the gas turbine stopping process, FIG. 1 ( b ) shows a rotational speed state, FIG. 1 ( c ) shows a metal temperature state and FIG. 1 ( d ) shows a state of stress occurring in a moving blade.
  • FIG. 2 are explanatory views of the transition of the occurrence of stress in a moving blade in a gas turbine stopping process in the prior art, wherein FIG. 2 ( a ) shows a load state, FIG. 2 ( b ) shows a of rotational speed state, FIG. 2 ( c ) shows a metal temperature state and FIG. 2 ( d ) shows a state of stress occurring in the moving blade.
  • FIG. 3 is a perspective view of a gas turbine moving blade in the prior art.
  • the load state shown in FIG. 1 ( a ) is the same as that of the prior art shown in FIG. 2 ( a ). That is, the load is 4/4 load (full load) until time t 1 , and then fuel is throttled to time t 2 , when the load becomes 0/4 load (no load). The 0/4 load is maintained until time t 3 , when the fuel is shut off, and then the load decreases rapidly to the zero state.
  • the metal temperature is kept slightly higher as a whole at the point B than at the point A.
  • the metal temperature is first kept constant until the time t 1 while the 4/4 load operation is performed. From the time t 1 , when the fuel starts to be throttled, until the time t 2 , when the load becomes the 0/4 load, the metal temperature decreases gradually as in the prior art case.
  • the stress at the point A of the moving blade 11 is the same as that of the prior art case until the time t 1 , as well as from the time t 1 to the time t 2 , when the load becomes the 0/4 load, as in the case of the metal temperature. But from the time t 2 , the operation is controlled to decrease the rotational speed, and the metal temperature is also decreased. Hence the influence both of the centrifugal force and the thermal stress is decreased considerably as compared with the prior art case.
  • the rotational speed is is controlled to decrease to about 60% of the rated rotational speed at the time t 3 when the fuel is shut off, at which point surge is hardly caused.
  • influence of the centrifugal force is decreased greatly to above 0.36, which equals 60% squared, of that in the prior art case.
  • the metal temperature is also decreased slightly, and hence the stress at the point A of the moving blade can be considerably decreased.
  • the control decreases the rotational speed starting from the time t 2 when the gas turbine comes to an operation of 0/4 load and to decrease it gradually to about 60% of the rated rotational speed at the time t 3 when the fuel is shut-off.
  • the fuel is also gradually decreased, hence in the process from the time t 3 of the fuel shut-off until the rotational speed is decreased to come to a stop, the influence of both the centrifugal force and the thermal stress is decreased, and thereby the stress caused at the point A of the moving blade 11 can be generally decreased as much as by about 40%, breakage of the moving blade does not occur, and the life thereof can be elongated by the stress mitigation.
  • the rotational speed control method in the gas turbine stopping process of the present invention can mitigate the stress due to both the centrifugal force as well as the thermal stress both occurring in the moving blade in the gas turbine stopping process, whereby breakage of the moving blade can be prevented, which results in a large elongation of the life thereof.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Control Of Turbines (AREA)
  • Engine Equipment That Uses Special Cycles (AREA)
  • Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
US09/380,460 1998-01-05 1998-12-28 Revolution speed control method in gas turbine shutdown process Expired - Lifetime US6253537B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP10-000186 1998-01-05
JP10000186A JPH11200895A (ja) 1998-01-05 1998-01-05 ガスタービン停止過程における回転数制御方法
PCT/JP1998/005988 WO1999035384A1 (fr) 1998-01-05 1998-12-28 Procede de controle de vitesse de revolution dans un processus d'arret de turbine a gaz

Publications (1)

Publication Number Publication Date
US6253537B1 true US6253537B1 (en) 2001-07-03

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Family Applications (1)

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US09/380,460 Expired - Lifetime US6253537B1 (en) 1998-01-05 1998-12-28 Revolution speed control method in gas turbine shutdown process

Country Status (6)

Country Link
US (1) US6253537B1 (fr)
EP (1) EP0979933B1 (fr)
JP (1) JPH11200895A (fr)
CA (1) CA2283862C (fr)
DE (1) DE69825983T2 (fr)
WO (1) WO1999035384A1 (fr)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090293493A1 (en) * 2004-06-30 2009-12-03 Yasuhiro Horiuchi Advanced humid air turbine power plant
US20100280733A1 (en) * 2009-05-04 2010-11-04 General Electric Company Gas turbine shutdown
US20100275608A1 (en) * 2009-05-04 2010-11-04 General Electric Company Systems and Methods for Rapid Turbine Deceleration
US20110232294A1 (en) * 2009-10-05 2011-09-29 Ross Steven A Methods and systems for mitigating distortion of gas turbine shaft
US8381507B2 (en) 2011-05-09 2013-02-26 General Electric Company Systems and methods for optimized gas turbine shutdown
US20140039775A1 (en) * 2010-02-23 2014-02-06 Williams International Co., L.L.C. System and method for contolling a single-spool turboshaft engine
WO2021233640A1 (fr) * 2020-05-19 2021-11-25 Forschungszentrum Jülich GmbH Fonctionnement d'une turbine à gaz à haute température et assemblage de turbine à gaz
US11199139B2 (en) * 2018-12-19 2021-12-14 Raytheon Technologies Corporation Gas turbine engine system bowed rotor start mitigation and wear reduction
US11306654B2 (en) 2018-12-19 2022-04-19 Raytheon Technologies Corporation Gas turbine engine system wear reduction

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100287944A1 (en) * 2009-05-13 2010-11-18 General Electric Company Availability improvements to heavy fuel fired gas turbines

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4201923A (en) * 1974-08-08 1980-05-06 Westinghouse Electric Corp. Combined cycle electric power plant and a gas turbine having improved megawatt load control
JPH0371142A (ja) 1989-08-10 1991-03-26 Mitsubishi Kasei Corp 電子写真用感光体
JPH0861095A (ja) 1994-08-19 1996-03-05 Abb Manag Ag 負荷遮断時にガスタービンの回転数を制御する方法及び該方法を実施するための装置
JPH08284615A (ja) 1995-04-14 1996-10-29 Toshiba Corp 一軸型コンバインドサイクル発電設備の制御方法及び装置
JPH0932583A (ja) 1995-07-18 1997-02-04 Toshiba Corp 発電設備の速度制御装置

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4010605A (en) * 1974-08-08 1977-03-08 Westinghouse Electric Corporation Accurate, stable and highly responsive gas turbine startup speed control with fixed time acceleration especially useful in combined cycle electric power plants
JPS5896131A (ja) * 1981-12-04 1983-06-08 Hitachi Ltd ガスタ−ビン速度制御方法
JPH0721885Y2 (ja) * 1989-11-13 1995-05-17 三菱重工業株式会社 ガスタービン用燃料流量制御装置

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4201923A (en) * 1974-08-08 1980-05-06 Westinghouse Electric Corp. Combined cycle electric power plant and a gas turbine having improved megawatt load control
JPH0371142A (ja) 1989-08-10 1991-03-26 Mitsubishi Kasei Corp 電子写真用感光体
JPH0861095A (ja) 1994-08-19 1996-03-05 Abb Manag Ag 負荷遮断時にガスタービンの回転数を制御する方法及び該方法を実施するための装置
JPH08284615A (ja) 1995-04-14 1996-10-29 Toshiba Corp 一軸型コンバインドサイクル発電設備の制御方法及び装置
JPH0932583A (ja) 1995-07-18 1997-02-04 Toshiba Corp 発電設備の速度制御装置

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090293493A1 (en) * 2004-06-30 2009-12-03 Yasuhiro Horiuchi Advanced humid air turbine power plant
US20100280733A1 (en) * 2009-05-04 2010-11-04 General Electric Company Gas turbine shutdown
US20100275608A1 (en) * 2009-05-04 2010-11-04 General Electric Company Systems and Methods for Rapid Turbine Deceleration
US8510013B2 (en) 2009-05-04 2013-08-13 General Electric Company Gas turbine shutdown
US20110232294A1 (en) * 2009-10-05 2011-09-29 Ross Steven A Methods and systems for mitigating distortion of gas turbine shaft
US8820046B2 (en) * 2009-10-05 2014-09-02 General Electric Company Methods and systems for mitigating distortion of gas turbine shaft
US20140039775A1 (en) * 2010-02-23 2014-02-06 Williams International Co., L.L.C. System and method for contolling a single-spool turboshaft engine
US9008943B2 (en) * 2010-02-23 2015-04-14 Williams International Co., L.L.C. System and method for controlling a single-spool turboshaft engine
US9157377B2 (en) 2010-02-23 2015-10-13 Williams International Co., L.L.C. System and method for controlling a single-spool turboshaft engine
US8381507B2 (en) 2011-05-09 2013-02-26 General Electric Company Systems and methods for optimized gas turbine shutdown
US11199139B2 (en) * 2018-12-19 2021-12-14 Raytheon Technologies Corporation Gas turbine engine system bowed rotor start mitigation and wear reduction
US11306654B2 (en) 2018-12-19 2022-04-19 Raytheon Technologies Corporation Gas turbine engine system wear reduction
US11976589B2 (en) 2018-12-19 2024-05-07 Rtx Corporation Gas turbine engine system wear reduction
WO2021233640A1 (fr) * 2020-05-19 2021-11-25 Forschungszentrum Jülich GmbH Fonctionnement d'une turbine à gaz à haute température et assemblage de turbine à gaz
US12385415B2 (en) 2020-05-19 2025-08-12 Forschungszentrum Jülich GmbH Operation of a gas turbine at a high temperature and gas turbine assembly

Also Published As

Publication number Publication date
WO1999035384A1 (fr) 1999-07-15
CA2283862A1 (fr) 1999-07-15
EP0979933A1 (fr) 2000-02-16
CA2283862C (fr) 2002-03-19
DE69825983T2 (de) 2005-09-08
EP0979933B1 (fr) 2004-09-01
EP0979933A4 (fr) 2002-01-30
DE69825983D1 (de) 2004-10-07
JPH11200895A (ja) 1999-07-27

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